(Peterson Electronics) Skychief B-150-A output?

[shadow]

Anyone know what these things should be putting out? I've got it hooked up to a radio shack power meter and if im reading it correctly, its putting out 30 watts deadkey and swings almost to 40.

[Night Crawler]

What kind of tubes does it have then I'll be able to tell you.

[shadow]

pair of Sylvania 6JB6

[Night Crawler]

What you have is the same as the palomar model 60 except they
use 6ju6's same as a 6jb6 40 watts is about right they rate theirs at 50 watts
with 3 watts drive. The output of a grounded grid linear depends on the
amount of drive and the amount of plate voltage some of the drive is also
part of your output. On the palomar their using 700 volts on the plate giving
50 watts rated output your amp might have only 500 volts on the plate resulting
in a lower output or you could have soft tubes and they need to be replaced.
Here is the manual for the palomar 60 with the schematic and tuning instructions.
[Please login or register to view this link]

[shadow]

thanks for the info and the link! i wonder if getting different tubes might change anything...

[Night Crawler]

If you plan on keeping it I would if the tubes are old there probably soft and
less efficient.

[shadow]

that sounds about right. is there a 'gold standard' for tubes? i keep reading about some tubes with black plates but im not sure what those are or where i can find them. would it do any good if i used a different type of tube altogether?

[Night Crawler]

I always had the best luck with the sylvania's. You could replace the 6jb6's
with 6lq6's there rated at double the output and you can double the drive to
them. Depending on how much current your power transformer can produce
and how hard you drive them up to 15 watts you might see more output it
all depends on the output current of the power transformer but you will still be
be able to double the drive to the 6lq6 also the tube is a little taller and the plate
cap is a wider then 6jb6 if you go with the 6lq6 make sure you have the room for
it and you will have to stretch the plate cap out a little.

[shadow]

Oops, thought i replied to your post but guess not. Thanks for the advise, the info, and the suggestions. I'm actually very interested in this tube amp. i've got a few questions tho...

...Depending on how much current your power transformer can produce
and how hard you drive them up to 15 watts

I'm assuming that the current is regulated by a resistor? or does one of the knobs on the front control the current to the tubes? This might be a broad question with a not-so-simple answer but, 1) how do I let more current get to the tubes and 2) how can i find out if my transformer can produce the current that the new tubes need?

muchas gracias for the help Night Crawler

[shadow]

ok the problem with my amp wasnt the tubes, it was my power meter. i went out and bought a new radio shack power meter and it shows 150 watts... excellent!